The root of madder plant has multiple uses, including therapeutic. The root is known to be astringent (pungent), aperient (mildly laxative), diuretic, cholagogue (a medication that promotes bile flow) and emmenagogue (a medicine that promotes menstrual discharge). While this plant is generally not used therapeutically, the roots have a reputation of being effective in treating jaundice, dropsy and amenorrhea (absence of menstruation). Rubia tinctoria or madder is particularly an excellent resource of anthraquinones that have the ability to bind calcium safely in our urinary tract and also considerably lessen the growth of calcium crystals in the urinary tract. This attribute of madder is very useful in preventing the formation of kidney stones. In addition, it has been proven that madder is effective in treating severe attacks of kidney stones, as it helps to diminish the size of kidney stones that have formed from before. Since the ancient times, the root of madder has been employed in the form of a vegetable dye to color cotton, wool, and silk as well as tan leather. The roots of the plant are harvested in the very first year of its existence to obtain the dye yielded by its root. The external brown layer of the plant yields an ordinary type of this dye, while the lower layer, which is yellow in color, yields a much refined dye. A mordant, usually alum, is used to fix the dye obtained from the madder root to the cloth. In addition, the fermented madder plant can also be used to dye clothes and leather, a process known as Fleurs de garance. People in France, also used the residue of the plant to make a spirit. The madder plant root encloses an acid known as ruberthyrin. The root is dried out, treated with acids or fermented to change ruberthyrin into different substances like alizarin, sugar and purpurin. These substances were isolated for the first time in 1826 by a French chemist named Pierre Jean Robiquet. Usually, purpurin does not have any color, but it turns red when liquefied in alkaline solutions. When it is combined with clay and thereafter treated using ammonia and alum, purpurin produces a vivid red color. You may dissolve the pounded madder roots in sulfuric acid to produce a dye after the solution is dried. This dye has been named after the French name for the madder plant - a garance. The yield of alizarin can also be increased employing another method - dissolve the roots of the plant in sulfuric acid once they have already been exploited to make dye. Through this process you can prepare a dye known as garanceux. A coloring can also be produced by treating the pounded roots of madder with alcohol. This dye contains about 40 to 50 times more alizarin found in madder roots. The pigment obtained from madder root is chemically known as alizarin and it belongs to the anthraquinone group. Way back in 1855, Professor Leonhardi of Dresden in Germany used this chemical to produce an ink called the alizarine. Some years later, in 1869, two German chemists Liebermann and Graebe produced artificial alizarin by synthesizing other chemicals and since 1871 this synthetic alizarin was produced industrially. In fact, this stopped madder cultivation. By the 20th century, this plant was cultivated just in few selected regions of France.
Madder plant (botanical name Rubia tinctoria) is indigenous to Europe. This herb is propagated by its seeds, ideally each seed sown in an individual small container packed with compost. The fresh seeds germinate more easily, but it is essential to protect the young plants from invasion of slugs, which are fond of consuming the madder seedlings. In addition, madder plants can also be propagated from cuttings. When the roots have established themselves, the plant creeps and spreads, clutching any nearby erect structure and may soon turn out to be invasive. You can obtain better reds from the madder plants provided you add lime to the soil they are growing in during the winter.
Several scientific studies have been undertaken to ascertain the health benefits of the madder root. According to the findings of one such research conducted in vitro, it was found that the madder root possesses anti-microbial properties. In another study, conducted on animals, it was found that the madder root has an anti-diarrheal effect in rodents.
Chemical analysis of the madder root has revealed that it encloses a number of chemicals, including purpurin, rubian, ruberythric acid, rubiadin, tannin, sugar and particularly alizarin. Pseudopurpurin contained by madder roots yields an orange hued dye, while xanthopurpurins yield a yellow dye. When added to water or alcohol, the roots impart a red color, slight scent and an astringent taste. Alizarin contained by madder root is considered to be the most fascinating coloring substance present in the plant. This chemical has now been named dihydroscyanthraquinone. This is present in the form of orange-red colored crystals and is quite not dissolved in water. However, it dissolves in alcohol, alkaline solutions, fixed oils and ether almost readily. The aqueous as well as alcoholic solutions of dihydroscyanthraquinone or alizarin have a rosy red hue, while the ethereal solution is golden-yellow. When dissolved in alkaline, it imparts blue color and when the solution is concentrated it has a violet hue. However, when the alkaline solution is greatly diluted, it becomes violet red. In fact, it is possible to produce a stunning rose-hued lake by dropping a mixture of alum and alizarin in the lake water.
Although the madder plants are ready for harvesting when they are three years old, the ideal age of the plants for harvesting is five years, as by this time, the roots have grown to be as thick as pencils. Roots of madder plants that have been in existence for about 15 years are often as thick as one inch across. Hence, it is advisable that you prepare at least three or even more beds for growing madder plants and plow them in alternation. According to a number of people, winter is the ideal time for digging out the madder roots, as the prickly foliage of the plant is dry during this time. Moreover, the roots contain maximum nutrients during winter. However, there are other people who say that it is best to dig the plants in August, as cleaning the roots is easier when they are kept in the open in the weather, which is good for a couple of weeks.